{"columns":["Value","Kind","Symbolic","Meaning"],"rows":[["0","Digit","---","No permission"],["1","Digit","--x","Execute only"],["2","Digit","-w-","Write only"],["3","Digit","-wx","Write and execute"],["4","Digit","r--","Read only"],["5","Digit","r-x","Read and execute"],["6","Digit","rw-","Read and write"],["7","Digit","rwx","Read, write and execute"],["400","Mode","r--------","Owner can read; nobody else has access. SSH private keys"],["600","Mode","rw-------","Owner can read and write. Private files, SSH keys, .env files"],["640","Mode","rw-r-----","Owner reads and writes, group reads. Shared config"],["644","Mode","rw-r--r--","Owner reads and writes, everyone reads. Web pages and most files"],["660","Mode","rw-rw----","Owner and group read and write"],["664","Mode","rw-rw-r--","Owner and group write, everyone reads"],["700","Mode","rwx------","Owner has full access. Private directories and ~/.ssh"],["750","Mode","rwxr-x---","Owner full, group reads and enters. Shared directories"],["755","Mode","rwxr-xr-x","Owner full, everyone reads and executes. Scripts, programs, web directories"],["775","Mode","rwxrwxr-x","Owner and group full, everyone reads and executes"],["777","Mode","rwxrwxrwx","Everyone can do everything. Almost never the right answer"],["4000","Special","--s------","Setuid: an executable runs as its owner, e.g. passwd"],["2000","Special","-----s---","Setgid: runs as the group; on a directory, new files inherit its group"],["1000","Special","--------t","Sticky bit: on a directory, only a file's owner can delete it, e.g. /tmp"],["1777","Special","rwxrwxrwt","World-writable directory with the sticky bit, the mode of /tmp"],["chmod u+x file","Command","","Add execute for the owner"],["chmod go-w file","Command","","Remove write from group and others"],["chmod a+r file","Command","","Add read for everyone"],["chmod -R 755 dir","Command","","Apply 755 to a directory and everything in it"]]}